Die and die holder



8- F. JUDGE 2,251,336

DIE AND DIE HOLDER Filed July 26, 1939 n 24 I9 I2 22 as l6 (ATTORNEYSPatented Aug. 5, 1941 DIE AND DIE HOLDER- Franklin Judge, Greenfield,Mass, assignor to Greenfield Tap and Die Corporation, a corporation ofMassachusetts ATE OFFICE Application July 26, 1939, Serial No. 286,575

2 Claims.

This invention relates to thread cutting diesand holders therefor andparticularly to such dies and holders in which the holder is adaptedradially to adjust the die sections accurately to determine the threaddimensions.

The object of the invention is to provide a convenient means forpredetermining the setting of the die to desired adjustment.

.A further object is to enable the operator to ascertain readily theadjustment necessary for a given depth of thread.

In the accompanying drawing:

Fig. 1 is a sectional elevation of the die and holder;

Fig. 2 is a plan view looking in the direction of arrow 2 in Fig. 1.

Referring to the drawing, Fig. 1 shows a threading device comprising aholder H), a die II, a cap I2, and a lock nut I3. The holder I6 isprovided with diametrically opposed lugs I5 adapted to be received inrecesses It in the inner face of die II.

The die II is provided with upward extended threading prongs or lands[1, threaded on the inside I8 and having a conical outer surface I9 sothat the end of the die is frusto-conical in shape. The cap I2 isprovided with an upper annular portion 20 and a lower portion 2|. Theupper annular portion 26) is provided with a conical recess 22 engagingthe conical outer surface I9 of the threading lands H. The lower annularportion 2| is internally threaded to fit externally threaded portion 23of the holder IE1.

The cap I2 fastened on the holder l bears against outer conical surface22 of lands ll, securing the die II in place against holder III withlugs I positioned in the recesses I6, the conically surfaced ends of thelands ll projecting through and beyond the forward end of the cap I2.The rotative and axial movement of the cap II relative to the holder I0provides a tightening pressure on the outer surface of lands H. Theprongs or lands II fiex under the tightening pressure of the cap I2 onthe outer surface 22, providing a means for adjusting the thread cut bythe die. As the cap I2 is tightened against die II the cutting bore 24of the die is lessened. The diameter of the threaded screw is determinedby the bore 24 of the threads I8 as set by the cap I2. When screws arethreaded by the die to close tolerances a setting is made of the cap l2and a sample screw threaded. If this is over or under the measurementsought, the die II is corrected by adjusting the setting of the cap I2.

In order to provide for the reading of the initial setting of the cap I2and the determination of the correct adjustment required to bring thescrew size within the tolerances allowed a scale 25 extends around thetop side of the upper annular portion 2t of the cap I2. The lines andnumbers of the scale 25 are added on the bevel side of the cap and eachland I1 is provided with a zero line 28, said zero lines being equallyspaced with relation to each other and the number of divisions of thescale 25 is some multiple of the number of the zero lines. Thus theposition of the rotating cap can be read against the zero line on any ofthe lands and the scale 25 may be graduated to any convenient part ofthe cap rotation corresponding to a fraction of the adjustment of thedie. For example, each scale division may represent one-thousandth of aninch of die adjustment and of the corresponding adjustment of the threaddepth. The graduations of scale 25 are evenly spaced and the totaladjustment plus or minus between successive zero lines is sufficient totake care of any normal readjustment of the die from the trial setting.

The graduation of the top of the cap 12 with a number divisible by four,corresponding to the four lands, provides means for reading the settingof the cap l2 on the die II and holder I ll from all zero lines 26 byreading the setting at any one of the lands. For instance, as shown herethere are thirty-six graduations; if the setting at land A is six, thesetting at land B is six plus the nine graduations between each land, orfifteen. The readings at lands C and D, correspondingly, are twenty-fourand thirtythree. 1

The provision of these graduations facilitates the process ofreadjusting the cap I2 on die II after a test screw has been threaded.Before making the trial the original setting of the cap I2 in relationto the Zero line on any land I1 is read. This setting will give thereadings on the other lands by adding or subtracting the number ofgraduations between each land. Thus the operator, knowing the correctionto be made after the sample threading can adjust the cap I2 on the dieII against any of the lands I1 whether the setting for that land wasoriginally read or not so that the readjustment may be made readilyWhatever the position of the holder with relation to the operator.

For instance, if the original setting was six at land A, it was fifteen,twenty-four, and thirtythree at lands B, C and D respectively. If thecorrection is plus one it can be made from any one of the zero lines,fifteen to sixteen at land B, twenty-four to twenty-five at land C,thirtythree to thirty-four at land D, six to seven at land A.

I claim:

1. An adjustable die structure comprising a die having a frusto-conicalend divided into separate lands relatively radially adjustable, of aholder for the die comprising a body portion and a relatively movablecap housing the die and having a forward end surrounding and contactingthe conically surfaced ends of the lands projecting through and beyondsaid forward end of the cap member whereby slight radial adjustment ofsaid die lands is efiected by rotative and .axial movement of the caprelative to the holder,

and a die marking at a corresponding point on each of said landsadjacent said cap, said die markings being equally angularly spaced withrelation to each other around the axis of the die, and a cooperating 360circular measuring scale on the end of said cap having the number of itsequally spaced divisions a multiple of the number of lands of the dieand showing the adjustment of the die sections by the position of saidcap divisions relative to each of said die markings.

2. An adjustable die structure as set forth in claim 1 in which theseparate lands of the die are integrally connected by an annular ring atthe base of the prongs.

FRANKLIN JUDGE.

